Which two statements are true about a buffer cache?

When a buffer is read from a buffer cache, it may be inconsistent and require undo data to make it consistent.

A buffer cache stores copies of data blocks from all files of the database.

Buffer access is kept efficient by maintaining a least recently used (LRU) list for dirty and clean buffers.

A buffer cache always resides completely in System Global Area (SGA).

A buffer cache contains exactly three pools: default, keep, and recycle pool.